Bicycle seat-post.



No. 650,393. Patented May 29, 1900.

w. H. HOLAHAN. BICYCLE SEAT POST.

(Application filed June 5, 1899.)

2 Sheets-Shut 2,

(No Model.)

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UNITED STATES;

PATE TD C WILLIAM i1. IIOLAIHIAN, or chrome, iLLINois;

BICYCLE SEAT-POST.

SPECIFICATION forming part of Letters Patent N 0. 650,393, dated May 29, 1900.

Application filed Juno 5, 1899. Serial No- 719,421. (N0 model.)

To all whom it may concern.-

Beit known that 1, WILLIAM H. HOLAHAN, of Chicago, in the county of Cook and State of Illinois, have invented certain new and useful Improvements in Bicycle Seat-Posts, of which the following is a full, clear, and ex act description, reference being had to the accompanying drawings, forming a part of this specification, in which similar letters of reference in the difierent figures indicate like parts.

One object of my invention is to so construct an expanding self-locking device for use in connection with bicycle seat-posts and handle-bar stems that the expanding elements may serve as a reinforcement to the tube into which they are inserted.

A further object is to so construct a fastening device to be used, preferably, in connection with handle-bars that the expansion members may be rigidly and positively secured in position, so as to insure the same against acci dental displacement, all of which is hereinafter more particularly described and claimed.

In the drawings, Figure 1 is a longitudinal vertical sectional view of my improved seatpost and part of the bicycle-frame. Fig. 2 is alike view showing a modified construction. Fig. 3 is asectional view taken upon the line 3 3, Fig. 1. Fig. 4 is a sectional view taken upon the line 4 4, Fig. 1. Figs. 5 and 6 are views corresponding to those shown in Figs. 1 and 2, showing modifications of said invention. Fig. 7 is a plan view of the seat-post stem as it would appear when the top bar is removed; and Fig. 8 is a vertical sectional view of a modified construction, showing said invention applied to a handle-bar, with means for positively securing the expansion members in position.

Referring to the drawings, a represents the usual bicycle-frame or supporting-tube, while 1) indicates the tubular seat-post stem adapted to be received therein. That portion of the stem which extends above the receiving socket of the frame is flattened, as shown at 0, (better represented in Figs. 4 and 7,) so as to form an elongated opening, into which may be fitted two flat expansion membersd e. Said expansion members are formed from blanks of sheet-steel preferably about threesixteenths of an inch in thickness, and the outer faces are intended to be parallel with each other, so that when placed within the tubular stem they may fit against the opposite sides thereof, as shown in the drawings. An elongated opening or slot f, Figs. 1, 5,

and 6, is formed in the top of the expansionmember 01 for the reception of a screw or rivet 9, (better shown in Fig. 4,) which passes through the top bar it and also through a bore in the part 0, thus forming a pivot or fulcrum for the top bar, to which the saddle is intended to be secured in the usual way.

tend to its lowest desirable limit without be- 7 ing arrested by the part c.

The expansion members cl 8 are provided with means, or their meeting faces are so formed with respect to each other, that when said members are moved longitudinally in 0pposite directions their outer faces are caused to be brought nearer together or moved farther away from each other in parallel planes.

This result is accomplished, preferably, by forming upon said faces a series of reverse inclines, or, in other words, a series of surfaces which are inclined in opposite directions with respect to each other in the respective members, as represented at 1 in Figs. 1 and 6. In the former figure said inclined faces are represented by sinuous lines, while in the latter they assume a zigzag form. When constructed in either manner, one member forms a counterpart to the other, and when two are fitted together,so that the opposite faces touch from end to end, as shown, it is manifest that the outerfaces areataminimumdistance from each other. Said members should be of such size that when thus adjusted the outer faces will fit accurately within the tubular stem.

WVith the rivet g extending through the part.

c and member d it is obvious that the latter will be maintained in a stationary position,

' member 6 withdrawn from the supporting-tube.

. merit.-

ally-opposite sides of the tube 1) causes the latter to expand into an oval form, as indicated in dotted lines in Fig. 3, thereby firmly securing the stem withinthe supporting-tube a. The expansion necessary to lockthe stem in place is necessarily very slight, and,'assu'm ing the parts to be properly fitted, would be scarcely perceptible, and hence upon releasing the pressure the stem would. assume its normal shape, thus enabling it to be readily This construction possesses the important advantage that it enables a T top bar to be used, so that the saddle may be adjusted either in the front or rear of the stem, the downward pressure in the former position serving to depress and in the latter to raise the member e and in both cases to lock the seat-post in the socket.

In Fig. 2 I have shown a modification of said device in which the expanding members d e are tapered in opposite directions. This construction necessitates the placing of the saddle upon one end only of the top bar, a

pressure upon the opposite end serving to produce an unlocking action.

In said lastnamed view I have also shown a means for an additional adjustment of the expanding members in order to cause the proper expansion under varying conditions, while maintaining the bar 72 substantially horizontal when the parts are locked. In order to accomplish this result, I shorten the member cl and insert a solid block m, of metal, in the upper end of the stem, into which block is tapped a rod n, which is extended through lugs o p, formed upon or secured to the side of the member (1 The lug 0 is detachable and is inserted between shoulders q 7', formed upon said rod. A lug sis bent inwardly from the lower end of the tube 1) and serves as a guide for the red at, which is passed loosely through it. The lower end of the rod is pro v'ided with a screw-head i to permit adjustdirection the member 01 is raised or lowered, thus providing for any extreme in adjustment which may be desired.

InFig. 5 I have shown a still further modification in which a series of inclined faces to are formed upon the member d all of which are oblique to the straight inner face n of the Within the spaces or pockets between the two I place a series of hardenedsteel balls w, which are preferably held in place by slightly grooving the respective surfaces upon which they bear. When the balls are in the respective positions shown, it is- As the rod is turned in one or another obvious that a downward pressure upon the outer end of the top bar will cause them to roll down the incline,thereby separating the members d e and producing the desired locking.

Fig. 8 shows my improved expanding device as I would construct it for application to the stem 7) of an ordinary handle-bar 17 The expansion members d e are secured to the handle-bar by means of bolts or rivets, as shown, and are so adjusted that when the stem isinserted within its socket and the handle-baris placedin a horizontal position the stem is expanded. A ferrule or band I) is tached to the handle-bar, said band being tapered, as shown at 6 and slotted at b to receive the upper-or flattened portion of the stem. Said stem is also provided witha lug c, which is adapted to fit loosely within the notch formed in the band I). The handle-bar is threaded at b to receive a nut H, which is reamed out, as shown, to fitthe tapered end of the band. When the nut is screwed into position, the lug c is engaged thereby, which serves to positively lock the handle-bar in place until the nut is removed, when the tilting of the handle-bar will serve to disengage the expansion members in the manner described.

An important and obvious advantage of my improved device is that the expansion members serve as a powerful reinforcement to the stem of the seat-post, while the latter in turn supplements said members and especially pro vides against their lateral displacement and serves to rigidly secure the top bar in place.

Having thus described my invention, 1'

claim-- 1. A device of the class described, in which is combined a tubular stem adapted to fit within the supporting-tube of the frame, a bar pivoted upon the upper end of said tubular stem, a fiat' expansion member rigidly secured within said tubular stem, a secondary flat expansion member having its upper end pivotally attached to said bar, said member being arranged to move longitudinally within said stem in the same plane with said primary member, the two being disposed to bear substantially throughout their length upon opposite inner longitudinal surfaces of said tubular stem, and means for causing said expansion members to expand or separate laterally when pressure is applied to one end of said bar, substantially as described.

2. g A device of the class described, in which is combined a tubular stem adapted to fit within the supporting-tube of the frame, a bar pivoted upon the upper end of said tubular stem, an expansion member rigidly se cured within said tubular stem, a secondary I expansion member having its upper end pivotally attached to said bar, said member be ing arranged to move longitudinally within said stem, means for causing said expansion members to expand when pressure is applied to one end of said bar, a lug formed upon and specification, in the presence of two subscribextending laterally from said tubular stem, ing witnesses, this 26. day of June, 1899. and a nut upon said bar for engaging said lug A and positively looking said expansion mem- WILLIAM HOIfAHAN' '5 bers in a clamped position, substantially as Witnesses:

described. D. H. FLETCHER, In testimony whereof I have signed this FLORENCE KING. 

